Probabilistic human health risk assessment of PCDD/Fs near municipal solid-waste incinerator using Monte Carlo analysis coupled with triangular fuzzy numbers.

PCDD/Fs are dioxins produced by waste incineration and pose risks to human health. We aimed to detail the health risks of airborne and soil PCDD/Fs near a municipal solid-waste incinerator (MSWI) for the surrounding population and develop a new model that improves upon existing methods. Thus, we conducted field sampling and then investigated a MSWI in the Pearl River Delta (2016-2018). Our results showed that the carcinogenic and non-carcinogenic risk values of PCDD/Fs exposed to residents in nearby areas were acceptable, with hazard index (HI) values lower than 1.0 and a total carcinogenic risk lower than 1.0E-6. Notably, the results raised concerns regarding higher non-carcinogenic risks in children than in adults. Comparative analysis of the frequency accumulation diagram, accumulated probability risk, and the absolute value of error (δ) between the 95% confidence interval (CI) and the 90% CI of the Monte Carlo stochastic simulation-triangular fuzzy number (MCSS-TFN) and the MCSS model, respectively, demonstrated that the MCSS-TFN exhibited less uncertainty than the MCSS model, regardless of the health risk value of PCDD/Fs in ambient air or in soil. This observation underscores the superiority of the MCSS-TFN model over other models in assessing the health risks associated with PCDD/Fs in situations with limited data. Our new method overcomes the limited dataset size and high uncertainty in assessing the health risks of dioxin substances, providing a more comprehensive understanding of their associated health risks than MCSS models.

Health risk assessment of trace metal(loid)s in agricultural soil using an integrated model combining soil-related and plants-accumulation exposures: A case study on Hainan Island, South China.

Traditional health risk assessment of trace metal(loid)s (TMs) in agricultural soil exclusively considers direct soil-related exposure and may underestimate the health risks they pose. In this study, the health risks of TMs were evaluated using an integrated model that combined soil-related and plant-accumulating exposures. A detailed investigation of common TMs (Cr, Pb, Cd, As, and Hg) coupled with probability risk analysis based on a Monte Carlo simulation was conducted on Hainan Island. Our results showed that, except for As, the non-carcinogenic risk (HI) and carcinogenic risk (CR) of the TMs were all within the acceptable ranges (HI < 1.0, and CR < 1E-06) for direct soil-related exposure to bio-accessible fractions and indirect exposure via plant accumulation (CR substantially lower than the warning threshold 1E-04). We identified crop food ingestion as the essential pathway for TM exposure and As as the critical toxic element in terms of risk control. Moreover, we determined that RfDo and SFo are the most suitable parameters for assessing As health risk severity. Our study demonstrated that the proposed integrated model combining soil-related and plant-accumulating exposures can avoid major health risk assessment deviations. The results obtained and the integrated model proposed in this study can facilitate future multi-pathway exposure research and could be the basis for determining agricultural soil quality criteria in tropical areas.

[The new applications of NMR technology in the field of characterization of surface properties of the material].

Nuclear magnetic resonance (NMR) technology has been developed continuely because of its rapid, accurate and high resolution advantages, The technology has become an important method to analyze the soil properties, and to identify the structure of matters, food analysis, medical imaging fields. This study summarized two aspects of the important applications of NMR in the characterization of the surface properties of materials. First, the use of NMR techniques for the adsorption, desorption and diffusion behaviors of polymer on solid particles (mainly SiO2 particles). Sencond, to investigate the wettability and water uptake progress of contaminated soils using NMR techniques. This study summarized the important applications of NMR techniques in the characterization of surface properties. It also showed the unique application in the field of polymer materials and environment. This study introduced the measured method for the relaxation time of substance using acorn surface area analyzer in the liquid environment. It reflect the surface properties and structural features of substance. It also provided data support for the explanation of environmental behaviors of contaminants and thus, it played an important role in the environmental field. Compared to the conventional BET method, acorn surface area analyzer showed the advantages in terms of conditions and time measurement. Especially, traditional BET method cannot get the information of the specific surface area of substances in the liquid directly, but acorn surface area analyzer solved the difficult problem. It is a new breakthrough in the field of characterization of the surface properties of materials by NMR in the liquid. We analyzed the application of acorn surface area analyzer in pharmaceuticals, cosmetic materials, electronic products because acorn surface area analyzer could reflects the important characteristics of the surface properties and structural features of substance. And we provide the prospective of the applications of NMR techniques in organic matter of soils, drug and natural products detecting.